Festo Генератор вакуума OVEM, дюймовый - Handbuch (Seite 67)

OVEM
Festo ć OVEM ć 1004b English 67
Variant Switch input Switch output B Switch output A Diagnosis
−2N Message
finished
Switch output
negative−switching
Pressure sensor
outputĂA
Switch output
negative−switching
Pressure sensor
outputĂB
Switch input
negative−switching
Message
on
p
Switch output
negative−switching
Diagnostic message
−NI ć Analogue output
4 Ū 20 mA
Vacuum
−NU ć Analogue output
0 Ū 10 V
Vacuum
Tab. 3: Variants of switch outputs
2.4 Method of operation of the air−save function (LS)
· Check whether the air−save function can be used (saving energy).
This function is only possible with units −CE and −OE. The air−save function is activated at the factory.
The air−save function can be switched off (è chapter 6.3.4).
If the desired threshold value 1 for the vacuum is reached, the vacuum generation will be switched off
automatically. A non−return valve prevents reduction of the vacuum. As a result of leakage (e.g. due to
rough work item surfaces), the vacuum will be reduced slowly. If the set threshold value 3 is not
reached, vacuum generation will be switched on automatically. Vacuum will be generated until the set
threshold value 1 is reached again.
Fig. 5: clarifies the method of operation of the air−save function. The pressure curve with the threshold
values and limits is represented in the upper part of the graph. The relevant signals In (control input
signal) and Out A (message signal outwards) are shown in the lower part of the graph.